Wyvern

The Wyvern is a dragon that is similar to a Drake in appearance, but larger and spawns around mountains.
It is an Uber Creature an sometimes also called Dragon Boss.
To tame it, a boss tribute is required, crafted with 3 Golden Treats, 1 Dragon trophy, 1 Megapithecus trophy and 1 Broodmother trophy, Or it can be tamed by using a Silver Treat. its base health is about 500,000, and can get to 2,000,000 easily.

A tip for earning the Boss Tribute, when Megaphitecus is not spawning: kill some Dodorexes, and you have a 33% chance of earning a Megapithecus trophy.

A tip for leveling a Wyvern, 1,000,000 health is always a good set stat for a Wyvern to go with. 15,000 stamina and about 1,000 damage is a good bet as well.